Worm Eats Man's Retina: 9 Terrible Parasites

The New York City Transit Authority immediately defended itself. But Edward Brownbear, lead education instructor for the housing department and the city's top bedbug authority, reportedly said that he himself had seen the bugs on the wooden benches of Manhattan's Union Square station and The Bronx's Fordham Road station -- as well as on the clothing of a passenger on a train.

At least one Manhattan pest control professional agreed at the time that bedbug infestation had been a growing problem in the city's subway system.

"I've been talking about it for five years," said Jeffrey Eisenberg, president of Pest Away Exterminating, adding that he had personally reported bedbug sightings to subway administrators seven to eight years before.

Efforts to track the critters have revealed that, after a long decline, bedbugs have rebounded in the United States in recent years. This is partly because of increased international travel. The tiny, nocturnal insects are able to live in both fibers and wood. They are also known for their bites, which cause itchy bumps on the skin.

But the bite can lead to more than an itch. According to reports from the U.S. Public Health Service, bedbugs are known to carry dozens of infectious diseases, from smallpox to the flu.

And where people are, the bugs are sure to follow, said Cindy Mannes, spokeswoman for the National Pest Management Association.

"If you think about large groups of people, in many cases this is how bedbugs are transported," Mannes said at the time. "I know they've been found in movie theaters and other strange places."

7) Guinea Worm

The horrific nature of a Guinea worm infection is perhaps best captured in its Latin name -- Dracunculus medinensis. Roughly translated, the term means "little dragon of the Mediterranean."

Despite its small size, the Guinea worm can cause excruciating pain. The pest infects a human host through contaminated drinking water. The larvae of the worm mature in one's stomach and reproduce in the intestines. The mature female worms migrate to the surface of the skin. There, the worms embed themselves, growing up to three feet in length.

Primarily found in the Middle East and many African countries, the Guinea worm enjoys a colorful history shared by few other parasites. It has been found during the dissection of Egyptian mummies and is well documented in ancient texts. There are even possible references to it in the Old Testament.

Some even believe that the Guinea worm was the inspiration for the design of the caduceus -- the serpent-entwined staff that is now the symbol of the medical profession. The theory springs from the fact that in the ancient world, the proper removal of the worm involved grabbing the exposed tail and gradually winding the body of the worm around a stick -- as pulling too hard would cause the worm to break, resulting in infection and inflammation. Thus, some believe, the symbol of the parasite twisted around a stick became synonymous with the healing arts.